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    <title>Document</title>
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        div
        {
            background-color:rgba(0,0,0,0.5);
            width: 500px;
            height: 500px;

            margin: 0 auto;

            background-image: url(./图片/小米平衡车.png);

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            background-position: center center;
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    <div>
        sb
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